OCR Text |
Show 1897.] NEW AFRICAN MAMMALS 433 maxillary processes slender, surpassing the nasals by about 5 m m . Frontal narrow, flat, without the peculiar hollows just inwards of the postorbital processes found in the allied species. Postorbital processes well-developed, succeeded behind by a deep notch, following which there is a strongly developed supplementary process on the squamosal. Brain-case comparatively long, much narrower than in gregorlanus. Anteorbital foramina high and open, the bony bridge over them comparatively slender; front edge of their outer wall nearly vertical. Malar less vertically produced than in gregorlanus. Teeth apparently as in gregorlanus, but too much worn for exact comparison. Posterior palate extending about 3 m m . behind the molars. Dimensions of the type, an aged female, in skin:- Head and body 420 m m . ; tail (imperfect at tip) 1 1 0 + ? ; hind foot 63. Skull-basal length 69, basilar length 61 ; greatest breadth 5 3; nasals 28 X 14 ; interorbital breadth 25 ; tip to tip of postorbital processes 30 ; intertemporal breadth 24; least breadth across brain-case behind zygomata 28-5 ; greatest ditto 37 ; palate-length from henselion 34 ; diastema 17 ; length of upper molar series 14. Hab. Nyika plateau, 6000-7000 ft. Mr. Thomas had named this interesting animal in honour of Mr. Sclater, at whose instigation the Nyasa explorations had been begun, and to whose efforts so much of their continued success had been due. T. sclaterl was unquestionably most nearly allied to the species discovered by Dr. Gregory in Kikuyu, from which region Mr. Jackson had recently sent the skin of a young example. This skin had a yellow throat, yellow inner sides of both fore and hind limbs, and yellow groins, these parts being white in T. sclaterl. Its fur was rather stiffer than in T. sclaterl, and its tail was scarcely longer than the hind foot, a character which if constant in the adult would form a good external mark of distinction between the two forms. With regard to Gerbillus bohml, Noack, of which two specimens wTere in the collection, M r . Thomas thought the difference in the character of the incisors from that found in typical Gerbillus rendered it convenient to form a special subgenus for the reception of the species, and this he proposed to call Gerbllllscus. As pointed out by Dr. Noack, the incisors had two very shallow and almost indistinguishable grooves on their faces, instead of the single deep groove found in all the true Gerbilles. Mr. Thomas also stated that an examination of a Petrodromus from Zomba in the collection had convinced him that, instead of containing only a single species, the genus might be readily divided into three species-one from Mombasa, Mandera, and the neighbouring parts of E. Africa proper ; one from the Rovuma River; and the third from the Zambesi and Shire Rivers. The last named might be considered the typical form, as whatever Peters's |